Self-test for matter: Solid

Choose the correct answer for each question.

1. The slope of the graph is equal to Strain Stress Force constant Young modulus Tension 2. Which of the followings about the stress and the strain of a wire is correct? (A = cross section area of the wire, e = extension, F = Tension, l = length of the wire) Stress = F / A, Strain = l / e Stress = F / A, Strain = e / l Stress = e / l, Strain = F / A Stress = l / e, Strain = A / F Stress = A / F, Strain = l / e 3. Which of the following expressions is correct? Young modulus = StressStrain Strain = StressYoung modulus Stress = StrainYoung modulus Stress =Young modulus / Strain Strain =Stress / Young modulus 4. If the length of a wire is doubled, with the same extension, the tension must be one forth of the original one half of the original one same as before twice of the original one four times of the original one 5. Referring to Q4, if now the cross section area is doubled and the extension remains the same, then the force must be one forth of the original one half of the original one same as before twice the original one four times of the original one 6. The area under the curve in the figure is the elastic potential energy stored in the stretched wire the tension the elastic potential energy per unit volume stored in the stretched wire the elastic potential energy per unit area stored in the stretched wire the strain 7. The area under the curve in the figure is the elastic potential energy stored in the stretched wire the tension the elastic potential energy per unit volume stored in the stretched wire the elastic potential energy per unit area stored in the stretched wire the strain 8. Which of the followings about the Young moduli of copper, steel, and rubber is correct? steel > copper > rubber steel > rubber > copper copper> steel > rubber copper> rubber > steel rubber > copper > steel 9. The figure shows the stress-strain curve of a material. ( = stress, u = strain, P = proportional limit, L = elastic limit, Y = yield point, M = maximum stress, B = breaking point) Which of the following statements is incorrect? In the region OP, the material obeys Hooke's law. In the region OL, the material returns to the original state if the stress is removed. In the region LY, the material undergoes elastic deformation. A permanent deformation OO' remains if the stress is removed at point Y. The length of YB reflects the ductility of the material. 10. The unit of Young modulus is N/m N/m2 N m m/N m2/N